The present invention relates generally to rotary shaft couplings and, more particularly, to a shaft coupling which connects a gear or sprocket driving member to a corresponding driven member.
Shaft gear couplings are known for interconnecting a rotatable driving shaft and/or toothed member of a machine with a generally coaxially positioned and rotatably driven shaft and/or toothed member, such that rotation of the driving shaft causes a corresponding rotation of the driven shaft via the coupling. The coupling allows for misalignment of the toothed members or shafts, such as axial offsets or angular misalignments or both. Shaft couplings are typically cylindrical couplings, which slide along the shafts into position over the toothed members, such as sprockets or gears, of the shafts, or are two sleeves which are bolted together about the toothed members. However, in order to couple the shafts together, one of the shafts may need to be removed or the shafts may need to be separated enough to fit the cylindrical coupler or sleeve onto the shafts. Additionally, because such a coupling is slidable onto the toothed members, it may require additional lock rings, bolts or the like to prevent sliding off the gear members during operation of the machine. Often, a middle element or membrane is positioned within the coupling to limit such longitudinal movement in both directions.
Some couplings include a plastic coupler which mounts to a driving shaft and receives rotary member therein which is mounted to another, generally coaxially positioned shaft. Such a coupling obviates the need for a second gear of sprocket member. However, because the coupling is all plastic, it may tend to slip or crack at the connection to the shaft, and is thus not applicable to applications which transmit higher torques between the shafts.
Other couplings have been developed which connect the two shafts via a chain coupling, whereby a chain is wrapped around the sprocket members of the shafts to retain the members together. Because chain couplings include a plurality of joints which bend to fit around the sprocket members, chain couplings typically require periodic lubrication to prevent the joints from binding over time. Additionally, many chain couplings further require a cover over the chain coupling to prevent dirt and other contaminants from collecting on the joints of the chain, which may inhibit performance of the coupling.
The present invention is intended to provide a coupling device for connecting a pair of rotary members, such that rotation of one of the members causes a corresponding rotation of the other member via the coupling device. The coupling device is a two piece coupling device, wherein the two pieces or halves may be easily positioned about the rotary members and secured together to retain the rotary members within the coupling device.
According to one aspect of the present invention, a coupling device for connecting a rotary-driving member to a rotary driven member comprises a first coupling member and a second coupling member. The rotary members include a plurality of teeth around a circumference thereof. The first and second coupling members include a plurality of teeth extending longitudinally therealong. The first and second coupling members have a shape that is generally semi-cylindrical, and include a pair of first and second edges extending longitudinally along opposite sides of the first and second coupling members. The second coupling member is connectable to the first coupling member about the rotary members along the first and second edges of the first and second coupling members. When connected, the first and second coupling members are adapted to non-rotatably retain the rotary members therewithin, whereby the plurality of teeth of the first and second coupling members are adapted to engage the plurality of teeth of the rotary members. The first and second coupling members are operable to limit longitudinal movement of the coupling device relative to the rotary members.
Preferably, the coupling members are secured together via a fastener or pin inserted at least partially through the first and second edges of the coupling members along each side thereof. Preferably, each coupling member includes a decreased circumference or diameter stop portion at one end, which limits longitudinal movement of the coupling member relative to the toothed rotary members. When the coupling members are connected together, the stop portion of one coupling member is at one end and the stop portion of the other coupling member is at the opposite end of the coupling device, such that each stop portion limits longitudinal movement of the coupling device in that particular direction.
According to another aspect of the present invention, a flexible coupling device for connecting a rotary driving member to a rotary driven member of a line shaft conveyor comprises a first coupling member and a second coupling member. The rotary members of the line shaft conveyor include a plurality of teeth around a circumference thereof. The first coupling member includes a plurality of teeth extending longitudinally therealong and first and second ends. The first coupling member has a shape that is generally a portion of a cylinder and comprises a flexible material. The second coupling member includes a plurality of teeth extending longitudinally therealong and first and second ends. The second coupling member has a shape that is generally another portion of the cylinder and also comprises a flexible material. The first and second coupling members are flexible and adapted to flex and wrap about the rotary driving and driven members. The plurality of teeth of the first and second coupling members are adapted to engage the plurality of teeth of the rotary members when the first and second coupling members are wrapped about the rotary member. The first and second coupling members are joined and securable together when the first and second coupling members are wrapped about the rotary members.
Preferably, the first and second coupling members define a generally continuous cylindrical casing when the first and second coupling members are wrapped about the rotary members. Preferably, the first and second coupling members include first and second longitudinal stop portions at each end of the coupling members. The first and second stop portions correspond with one another to define first and second stop walls at opposite ends of the flexible coupling device when the coupling members are secured together. The stop walls limit longitudinal movement of the flexible coupling device relative to the rotary members. The first and second coupling members may include overlapping end portions at the first and second ends thereof for a fastening member to be insertable through a passageway in the overlapping end portions to secure the first and second coupling members together. The first and second coupling members may also be pivotable about one of the fastening members to wrap the flexible coupling device about the rotary members, while the other of the fastening members is insertable to secure the first and second coupling members about the rotary members. Preferably, the first and second coupling members comprise a rubber material, such as neoprene rubber or the like.
According to another aspect of the present invention, a coupling device for connecting a rotatable shaft to a sprocket member includes a rotary member and a coupling member. The sprocket member has a plurality of teeth around a circumference thereof. The rotary member includes a central portion having a mounting opening therethrough and a plurality of teeth extending from the rotary member, the mounting opening being adaptable to receive the rotatable shaft therethrough for non-rotatably securing the coupling device to the rotatable shaft and being rotatable therewith. The coupling member is molded about the rotary member. The teeth of the rotary member are within the coupling member to non-rotatably retain the rotary member within the coupling member. The coupling member includes a sprocket member receiving portion extending longitudinally from the rotary member for non-rotatably receiving the sprocket member therewithin. The sprocket member receiving portion includes a plurality of teeth extending longitudinally therealong. The first coupling member has a generally cylindrical shape. The plurality of teeth of the sprocket member receiving portion are adapted to engage the plurality of teeth of the sprocket member when the sprocket member is received within the sprocket member receiving portion.
Therefore, the present invention provides a coupling device which may be easily secured about a pair of corresponding rotary members. Because the coupling device comprises two pieces or halves, the rotary members need not be separated or removed to position the coupling device about the rotary members for connection thereto. Additionally, the decreased circumference stop portions limit or substantially preclude longitudinal movement of the coupling device relative to the rotary members beyond an operable range of the coupling device.
These and other objects, advantages, purposes and features of this invention will become apparent upon review of the following specification in conjunction with the drawings.